They will do whatever is selling at the time. Back in 2008 Ubi's casual lineup (Imagine, petz etc) was pretty strong and driving most of their profits so they opened two studios in Brazil to pump out even more crap in less time. Their plan was to start with a core team of 20 people and then grow to 200 after 4 years. After 2 years, the tides changed, nobody was buying those games anymore and they decided to focus on their "core" franchises again. They didn't think twice before shutting down both studios and laying off people around the world when that happened.
All I'm saying is, even if they do create 500 dev jobs now if those jobs are in mobile or something very specific they won't think twice before laying off those people when the tides change again. And that doesn't apply to Ubi only, every time I see news that some game studio is ramping up like mad in a short amount of time that raises a red flag for me.
If there's one thing I learned from the Ubi lay off is to always be prepared for one, this industry is extremely volatile and you can lose your job quickly when things don't go as planned.